(Patrick) Lange-Bertalot 2000      Category: Symmetrical biraphid
TYPE SPECIES: Decussata placenta (Patrick) Lange-Bertalot & Metzeltin in Lange-Bertalot




CLASS: Bacillariophyceae
  ORDER: Naviculales

  1. Striae punctate
  2. Striae appear to form an "X" pattern
  3. Valves linear to linear-lanceolate

Decussata valves are linear to linear-lanceolate, with slightly rostrate ends. The striae are punctate, comprised of evident areolae which cross at an oblique angle, forming a characteristic “X” pattern.

Decussata includes two species, including the former Navicula placenta. Decussata placenta grows in low nutrient, slightly acidic seeps in Iowa. It is also known from moss and aerophilic habitats.

Cite This Page:
Spaulding, S., and Edlund, M. (2008). Decussata. In Diatoms of the United States. Retrieved July 28, 2015, from

Contributor: Sarah Spaulding | Mark Edlund - December 2008


April 17th, 2012 - Correction of authorship

The authorship of the genus Decussata was previously given as (Patrick) Lange-Bertalot. It was corrected to (Patrick) Lange-Bertalot & Metzeltin in Lange-Bertalot. S. Spaulding